The present application relates to hydraulic systems, and more particularly to a regenerative drive for hydraulic cylinders in hydrostatic circuits in a drilling rig.
In a typical drilling operation, the kinetic energy of lowering the drill string is converted to heat through some form of braking mechanism, either mechanical or hydraulic. Typically, this energy is lost and not recovered. It requires additional energy to raise the drill head in order to add or to unload another section of drill steel.
The lost energy from lowering the drill string can be considerable. Harnessing the energy within a hydrostatic system for further use by another hydraulic machine is desirable. A regenerative drive can be used to recover and store the kinetic energy generated by lowering the drill string. This stored energy can then used to raise the drill head or to operate other machinery.